In order to assure that consumer items such as food products, beverages, pharmaceuticals, and the like have not been opened or tampered with prior to purchase, it is very desirable to provide a tamper-evident seal on the containers for such items. Such tamper-evident seals, sometimes referred to as tamper bands, are ordinarily applied to containers after they have been sealed such that any opening or attempted opening of the container results in visually discernible alteration or destruction of the tamper-evident seal.
One type of tamper-evident seal used on containers comprises a heat-shrinkable member applied to each container. Such heat-shrinkable members are typically formed as annular shaped, cylindrical tubular segments which are positioned on the containers, and are thereafter heated so that the members heat-shrink into conformance with the associated containers. For tamper-indication, the heat-shrinkable members are usually positioned such that they shrink into close-fitting association with the lid or like closure of the container so that removal or attempted removal of the lid permanently deforms the associated heat-shrinkable member. For other applications, heat-shrinkable members are fitted to containers so as to form closely-fitting sleeves for the containers. Such sleeves can be provided for protecting and rigidifying the container itself, and/or the heat-shrinkable members can be suitably printed so as to form labels for the containers. If desired, a heat-shrinkable member can be fitted to a container for multiple purposes, such as to provide a combination protective sleeve/tamper band.
Copending U.S. patent application Ser. No. 451,401, filed Dec. 20, 1982, discloses a method and apparatus for forming spirally-wound, heat-shrinkable members in the form of tubular segments each having a generally cylindrical configuration. The method and apparatus of this copending application permit highly efficient and inexpensive manufacture of heat-shrinkable members suited for subsequent application to containers by heat-shrinking. Accordingly, it is highly desirable to provide a method and apparatus for efficiently and continuously applying heat-shrinkable members to containers to provide the containers with tamper-bands, protective sleeves, or the like.